Lexus ES: Pressure Control Solenoid "C" Actuator Stuck Off (P07957F)

Lexus ES (XZ10) Service Manual / Drivetrain / Ub80f (automatic Transmission / Transaxle) / Automatic Transaxle System / Pressure Control Solenoid "C" Actuator Stuck Off (P07957F)

DESCRIPTION

Based on signals from the transmission revolution sensors (NT and NC), the actual gear is detected.

The ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical malfunctions of the solenoid valves, transmission valve body assembly and automatic transaxle assembly (clutch, brake, gear, etc.).

Actual gear when solenoid (SL3) valve malfunction occurs (without fail-safe control):

ECM commanded gear	1st	2nd	3rd	4th	5th	6th	7th	8th
*: Neutral
Actual gear during SL3 stuck ON malfunction	3rd	3rd	3rd	3rd	3rd to 5th	7th	7th	7th
Actual gear during SL3 stuck OFF malfunction	1st	2nd	N*	4th	5th	6th	N*	8th

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory	Note
P07957F	Pressure Control Solenoid "C" Actuator Stuck Off	All of the following conditions are met (2-trip detection logic): Engine coolant temperature is 40°C (104°F) or higher. ATF temperature is -10°C (14°F) or higher. The vehicle is being driven with the shift lever in D. No malfunctions are detected in the solenoid (SL1, SL2, SL3, SL4, SL5, SL6, SL, SLU and SLT) valves, transmission revolution sensors (NT and NC), coolant temperature sensor, oil temperature sensor, knock sensor, crankshaft position sensor circuits, electronic throttle or CAN communication system. Any of the following conditions are met: When the ECM commands the transaxle to shift to 1st, 2nd, 4th or 5th gear, the actual gear changes to 3rd gear for 0.8 seconds or more. When the ECM commands the transaxle to shift to 6th or 8th gear, the actual gear changes to 7th gear for 0.8 seconds or more. When the ECM commands the transaxle to shift to 3rd or 7th gear, the engine overruns (neutral status) for 0.5 seconds or more.	Solenoid (SL1) valve Solenoid (SL2) valve Solenoid (SL3) valve Solenoid (SL4) valve Solenoid (SL5) valve Solenoid (SL6) valve Solenoid (SL) valve Solenoid (SLU) valve Solenoid (SLT) valve Transmission valve body assembly Torque converter assembly Automatic transaxle assembly (clutch, brake, gear, etc.)	Comes on	DTC stored	SAE Code: P0796

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

Note

P07957F

Pressure Control Solenoid "C" Actuator Stuck Off

All of the following conditions are met (2-trip detection logic):

Engine coolant temperature is 40°C (104°F) or higher.
ATF temperature is -10°C (14°F) or higher.
The vehicle is being driven with the shift lever in D.
No malfunctions are detected in the solenoid (SL1, SL2, SL3, SL4, SL5, SL6, SL, SLU and SLT) valves, transmission revolution sensors (NT and NC), coolant temperature sensor, oil temperature sensor, knock sensor, crankshaft position sensor circuits, electronic throttle or CAN communication system.
Any of the following conditions are met:
- When the ECM commands the transaxle to shift to 1st, 2nd, 4th or 5th gear, the actual gear changes to 3rd gear for 0.8 seconds or more.
- When the ECM commands the transaxle to shift to 6th or 8th gear, the actual gear changes to 7th gear for 0.8 seconds or more.
- When the ECM commands the transaxle to shift to 3rd or 7th gear, the engine overruns (neutral status) for 0.5 seconds or more.

Solenoid (SL1) valve
Solenoid (SL2) valve
Solenoid (SL3) valve
Solenoid (SL4) valve
Solenoid (SL5) valve
Solenoid (SL6) valve
Solenoid (SL) valve
Solenoid (SLU) valve
Solenoid (SLT) valve
Transmission valve body assembly
Torque converter assembly
Automatic transaxle assembly (clutch, brake, gear, etc.)

Comes on

DTC stored

SAE Code:

P0796

DTC Detection Condition Patterns:

		Vehicle Condition
		Pattern 1	Pattern 2	Pattern 3	Pattern 4
Diagnostic Condition	Engine coolant temperature is 40°C (104°F) or higher.	○	○	○	○
	ATF temperature is -10°C (14°F) or higher.	○	○	○	○
	The vehicle is being driven with the shift lever in D.	○	○	○	○
	No malfunctions are detected in the solenoid (SL1, SL2, SL3, SL4, SL5, SL6, SL, SLU and SLT) valves, transmission revolution sensors (NT and NC), coolant temperature sensor, oil temperature sensor, knock sensor, crankshaft position sensor circuits, electronic throttle or CAN communication system.	○	○	○	○
Malfunction Condition	When the ECM commands the transaxle to shift to 1st gear, the actual gear changes to 3rd gear.	○	-	-	-
	When the ECM commands the transaxle to shift to 2nd gear, the actual gear changes to 3rd gear.	-	○	-	-
	When the ECM commands the transaxle to shift to 4th gear, the actual gear changes to 3rd gear.	-	-	○	-
	When the ECM commands the transaxle to shift to 5th gear, the actual gear changes to 3rd to 5th gear.	-	-	-	○
Duration		0.8 seconds or more	0.8 seconds or more	0.8 seconds or more	0.8 seconds or more
Detection Logic		2-trip detection logic	2-trip detection logic	2-trip detection logic	2-trip detection logic

DTC Detection Condition Patterns:

		Vehicle Condition
		Pattern 5	Pattern 6	Pattern 7	Pattern 8
Diagnostic Condition	Engine coolant temperature is 40°C (104°F) or higher.	○	○	○	○
	ATF temperature is -10°C (14°F) or higher.	○	○	○	○
	The vehicle is being driven with the shift lever in D.	○	○	○	○
	No malfunctions are detected in the solenoid (SL1, SL2, SL3, SL4, SL5, SL6, SL, SLU and SLT) valves, transmission revolution sensors (NT and NC), coolant temperature sensor, oil temperature sensor, knock sensor, crankshaft position sensor circuits, electronic throttle or CAN communication system.	○	○	○	○
Malfunction Condition	When the ECM commands the transaxle to shift to 6th gear, the actual gear changes to 7th gear.	○	-	-	-
	When the ECM commands the transaxle to shift to 8th gear, the actual gear changes to 7th gear.	-	○	-	-
	When the ECM commands the transaxle to shift to 3rd gear, the engine overruns (neutral status).	-	-	○	-
	When the ECM commands the transaxle to shift to 7th gear, the engine overruns (neutral status).	-	-	-	○
Duration		0.8 seconds or more	0.8 seconds or more	0.5 seconds or more	0.5 seconds or more
Detection Logic		2-trip detection logic	2-trip detection logic	2-trip detection logic	2-trip detection logic

HINT:

This DTC is stored when any of the above detection patterns is met.

MONITOR DESCRIPTION

The ECM commands gear shifts by turning the solenoid valves on and off. According to the input shaft revolution (speed) and output shaft revolution (speed), the ECM detects the actual gear (1st, 2nd, 3rd, 4th, 5th, 6th, 7th or 8th gear). When the gear commanded by the ECM and the actual gear are not the same, the ECM illuminates the MIL and stores a DTC.

MONITOR STRATEGY

Related DTCs	P0796: Solenoid (SL3) valve/OFF malfunction Solenoid (SL3) valve/ON malfunction
Required sensors/components	Solenoid (SL3) valve
Frequency of operation	Continuous
Duration	OFF malfunction (A) and (B): 0.5 sec. OFF malfunction (C): - ON malfunction (A), (B), (C), (D) and (E): 0.8 sec. ON malfunction (F): -
MIL operation	2 driving cycles
Sequence of operation	None

TYPICAL ENABLING CONDITIONS

All

The monitor will run whenever the following DTCs are not stored	P0717, P07BF, P07C0 (Turbine speed sensor circuit) P0793, P07C5, P07C6 (Intermediate shaft speed sensor circuit) P0962, P0963 (Solenoid (SL1) valve circuit) P0966, P0967 (Solenoid (SL2) valve circuit) P0970, P0971 (Solenoid (SL3) valve circuit) P2814, P2815 (Solenoid (SL4) valve circuit) P281D, P281E (Solenoid (SL5) valve circuit) P08C1, P08C2 (Solenoid (SL6) valve circuit) P2769, P2770 (Solenoid (SL) valve circuit) P2763, P2764 (Solenoid (SLU) valve circuit) P2720, P2721 (Solenoid (SLT) valve circuit) P0117, P0118 (ECT sensor circuit) P0335, P0337, P0338 (Crankshaft position sensor circuit) P0712, P0713 (ATF temperature sensor circuit (TFT sensor)) P0327, P0328, P0332, P0333 (KCS sensor circuit) P0121, P0122, P0123, P0222, P0223, P0604, P0606, P060A, P060B, P060D, P060E, P061E, P0657, P0658, P2102, P2103, P2111, P2112, P2119, P2135 ((ETCS) Electronic throttle control system) U0100 (CAN communication system)
Shift position	"D", "not R" and "not N"
Elapsed time since shift lever moved from "N" to "D"	4 sec. or more
ATF temperature	-10°C (14°F) or more
Engine	Starting
Fail-safe function does not operate due to the following malfunctions:	-
Solenoid (SL1) valve	OFF or ON malfunction (P0746)
Solenoid (SL2) valve	OFF or ON malfunction (P0776)
Solenoid (SL3) valve	OFF or ON malfunction (P0796)
Solenoid (SL4) valve	OFF or ON malfunction (P2808)
Solenoid (SL5) valve	OFF or ON malfunction (P2817)
Solenoid (SL6) valve	OFF or ON malfunction (P08BB)
Solenoid (SLT) valve	OFF malfunction (P2714)
Solenoid (SLU) valve	ON malfunction (P2757)
Solenoid (SL) valve	ON malfunction (P0741)
All shift solenoids	Not being stopped
Neutral command flag	Not met

OFF malfunction (A)

ECM selected gear	7th
Neutral state detected when 3rd gear commanded	-
Vehicle stop check	Fixed

OFF malfunction (B)

ECM selected gear	3rd
Neutral state detected when 7th gear commanded	-
Vehicle stop check	Fixed

ON malfunction (A)

ECM selected gear	1st
Vehicle speed	2 km/h (1.2 mph) or more and less than 38 km/h (23.6 mph)
Throttle valve opening angle	7% or more at engine speed 2000 rpm (conditions vary with engine speed)
Calculated load value	-
- When A/C off	16% or more
- When A/C on	19% or more
ECT	40°C (104°F) or more
Spark advance from MAX. retard timing by KCS control	0 °CA or more
Calculated input torque	0 Nm (0 kgfcm, 0 ft.*lbf) or more

ON malfunction (B)

ECM selected gear	2nd
Vehicle speed	2 km/h (1.2 mph) or more
Throttle valve opening angle	7% or more at engine speed 2000 rpm (conditions vary with engine speed)
Calculated load value	-
- When A/C off	16% or more
- When A/C on	19% or more
ECT	40°C (104°F) or more
Spark advance from MAX. retard timing by KCS control	0 °CA or more
Calculated input torque	0 Nm (0 kgfcm, 0 ft.*lbf) or more

ON malfunction (C)

ECM selected gear	4th
Vehicle speed	2 km/h (1.2 mph) or more
Throttle valve opening angle	7% or more at engine speed 2000 rpm (conditions vary with engine speed)
Calculated load value	-
- When A/C off	16% or more
- When A/C on	19% or more
ECT	40°C (104°F) or more
Spark advance from MAX. retard timing by KCS control	0 °CA or more
Calculated input torque	0 Nm (0 kgfcm, 0 ft.*lbf) or more

ON malfunction (D)

ECM selected gear	6th
Vehicle speed	2 km/h (1.2 mph) or more
Throttle valve opening angle	7% or more at engine speed 2000 rpm (conditions vary with engine speed)
Calculated load value	-
- When A/C off	16% or more
- When A/C on	19% or more
ECT	40°C (104°F) or more
Spark advance from MAX. retard timing by KCS control	0 °CA or more
Calculated input torque	0 Nm (0 kgfcm, 0 ft.*lbf) or more

ON malfunction (E)

ECM selected gear	8th
Vehicle speed	2 km/h (1.2 mph) or more
Throttle valve opening angle	7% or more at engine speed 2000 rpm (conditions vary with engine speed)
Calculated load value	-
- When A/C off	16% or more
- When A/C on	19% or more
ECT	40°C (104°F) or more
Spark advance from MAX. retard timing by KCS control	0 °CA or more
Calculated input torque	0 Nm (0 kgfcm, 0 ft.*lbf) or more

Neutral state flag:

Turbine speed - output speed x (ECM selected gear ratio)

1000 rpm or more

Neutral state detection:

Neutral state flag

Any of the following conditions are met: Condition (a) or (b)
- Condition (a)
  
  ECM selected gear
  
  3rd
  
  Output speed x 5th gear ratio
  
  Less than 6500 rpm
  
  Condition (b)
  
  ECM selected gear
  
  7th
  
  Turbine speed - output speed x 3rd gear ratio
  
  More than 50 rpm
  
  Output speed x 5th gear ratio
  
  Less than 6500 rpm

Vehicle stop check:

Vehicle speed

Less than 0 km/h (0 mph)

Neutral command flag:

Engine speed	7200 rpm or more
Turbine speed	7200 rpm or more

Any of the following conditions are met: Condition (a) or (b)
- Condition (a)
  
  ECM selected gear
  
  6th or 7th or 8th
  
  Output speed x 5th gear ratio
  
  7200 rpm or more
  
  Condition (b)
  
  ECM selected gear
  
  4th or 5th
  
  Output speed x 3rd gear ratio
  
  7200 rpm or more

TYPICAL MALFUNCTION THRESHOLDS

OFF malfunction

Any of the following conditions are met: OFF malfunction (A), (B) or (C) OFF malfunction (A) and (B)

Neutral state flag

ON

OFF malfunction (C)

Solenoid (SLT) valve

ON malfunction
- Any of the following conditions are met: Condition (a) or (b) Condition (a)
  
  ECM selected gear
  
  3rd
  
  3rd gear pass detection
  
  Not fixed after transition to latest gear
  
  Condition (b)
  
  ECM selected gear
  
  7th
  
  7th gear pass detection
  
  Not fixed after transition to latest gear

ON malfunction

Any of the following conditions are met: ON malfunction (A), (B), (C), (D), (E) or (F) ON malfunction (A), (B) and (C)

Any of the following conditions are met

(a) or (b)

(a) Turbine speed/Output speed (NT/NO)

1.817 or more and 2.082 or less

(When output speed less than 380 rpm)

(b) Turbine speed - Output speed x 3rd gear ratio

-50 rpm or more and 50 rpm or less

(When output speed 380 rpm or more)

ON malfunction (D) and (E)

Any of the following conditions are met

(a) or (b)

(a) Turbine speed/Output speed (NT/NO)

0.744 or more and 0.876 or less

(When output speed less than 780 rpm)

(b) Turbine speed - Output speed x 7th gear ratio

-50 rpm or more and 50 rpm or less

(When output speed 780 rpm or more)

ON malfunction (F)

Solenoid (SLT) valve

ON malfunction

Any of the following conditions are met: Condition (a), (b) or (c) Condition (a)

ECM selected gear

4th

4th gear pass detection

Not fixed after transition to latest gear

Condition (b)

ECM selected gear

5th

5th gear pass detection

Not fixed after transition to latest gear

Condition (c)

ECM selected gear

8th

8th gear pass detection

Not fixed after transition to latest gear

Neutral state flag:

Turbine speed - Output speed x (ECM selected gear ratio)

1000 rpm or more

CONFIRMATION DRIVING PATTERN

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

HINT:

After repairs have been completed, clear the DTCs and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
When clearing the permanent DTCs, refer to the Clear Permanent DTC procedure.
Click here

Connect the Techstream to the DLC3.
Turn the engine switch on (IG) and turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the engine switch off and wait for 2 minutes or more.
Turn the engine switch on (IG) and turn the Techstream on.
Start the engine.
Perform the D Position Shift Test inspection in Road Test. [*1]
Click here

HINT:

[*1] : Normal judgment procedure.

The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
Stop the vehicle.
Enter the following menus: Powertrain / Transmission / Utility / All Readiness.
Input the DTC: P07957F.

Check the DTC judgment result.

Techstream Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

HINT:

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
If the judgment result shows INCOMPLETE or N/A, perform the normal judgment procedure again.

CAUTION / NOTICE / HINT

NOTICE:

Perform the universal trip to clear permanent DTCs.
Click here
Perform registration and/or initialization when parts related to the automatic transaxle are replaced.
Click here

PROCEDURE

1.	CHECK DTC OUTPUT (IN ADDITION TO DTC P07957F)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(d) Enter the following menus: Powertrain / Transmission / Trouble Codes.

Powertrain > Transmission > Trouble Codes

(e) Read the DTCs using the Techstream.

Result	Proceed to
DTC P07957F and DTC P07457F, P07407E, P07757F, P08BA7F, P27137F, P28077F and/or P28167F are output	A
Only DTC P07957F is output	B
DTCs other than P07457F, P07407E, P07757F, P07957F, P08BA7F, P27137F, P28077F and P28167F are also output	C

HINT:

If any DTCs other than P07457F, P07407E, P07757F, P07957F, P08BA7F, P27137F, P28077F and P28167F are output, perform troubleshooting for those DTCs first.
If a solenoid valve is stuck ON or OFF, DTCs for several solenoid valves including the malfunctioning solenoid valve will be stored.

GO TO STEP 3

GO TO DTC CHART

2.	CLEAR DTC AND PERFORM STALL SPEED TEST

(a) Clear the DTCs.

Powertrain > Transmission > Clear DTCs

HINT:

Write down the currently output DTCs before clearing them.

(b) Perform the stall speed test.

Click here

Test Condition	Proceed to
Stall speed test can be performed	A
Stall speed test cannot be performed	B

GO TO STEP 5

3.	INSPECT SOLENOID (SL1), (SL2), (SL3), (SL4), (SL5) AND (SL6) VALVE

(a) Remove the solenoid (SL1), (SL2), (SL3), (SL4), (SL5) and (SL6) valves.

Click here

*a	Component without harness connected (Solenoid (SL1), (SL2), (SL3), (SL4), (SL5) and (SL6) Valves)

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
Solenoid (SL1) valve connector terminal 1 - terminal 2	20°C (68°F)	5.0 to 5.6 Ω
Solenoid (SL2) valve connector terminal 1 - terminal 2	20°C (68°F)	5.0 to 5.6 Ω
Solenoid (SL3) valve connector terminal 1 - terminal 2	20°C (68°F)	5.0 to 5.6 Ω
Solenoid (SL4) valve connector terminal 1 - terminal 2	20°C (68°F)	5.0 to 5.6 Ω
Solenoid (SL5) valve connector terminal 1 - terminal 2	20°C (68°F)	5.0 to 5.6 Ω
Solenoid (SL6) valve connector terminal 1 - terminal 2	20°C (68°F)	5.0 to 5.6 Ω

(c) Connect a positive (+) lead from the battery with a 21 W bulb to terminal 1 and a negative (-) lead to terminal 2 of the solenoid valve connector. Check that the valve moves and makes an operating sound.

OK:

Valve moves and makes an operating sound.

REPLACE SOLENOID (SL1), (SL2), (SL3), (SL4), (SL5) OR (SL6) VALVE

4.	INSPECT SOLENOID (SL) VALVE

(a) Remove the solenoid (SL) valve.

Click here

*1	Solenoid (SL) Valve

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
Solenoid (SL) valve connector terminal - Solenoid (SL) valve body	20°C (68°F)	11 to 15 Ω

(c) Connect a positive (+) lead from the battery to the terminal of the solenoid valve connector, and a negative (-) lead to the solenoid body. Check that the valve moves and makes an operating sound.

OK:

Valve moves and makes an operating sound.

REPLACE SOLENOID (SL) VALVE

5.	INSPECT SOLENOID (SLT) VALVE

(a) Remove the solenoid (SLT) valve.

Click here

*a	Component without harness connected (Solenoid (SLT) Valve)

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
Solenoid (SLT) valve connector terminal 1 - terminal 2	20°C (68°F)	5.0 to 5.6 Ω

OK:

Valve moves and makes an operating sound.

REPLACE SOLENOID (SLT) VALVE

6.	INSPECT TRANSMISSION VALVE BODY ASSEMBLY

(a) Inspect the transmission valve body assembly.

Click here

OK:

There is no foreign matter on each valve and they operate smoothly.

REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY

7.	INSPECT TORQUE CONVERTER ASSEMBLY

(a) Inspect the torque converter assembly.

Click here

OK:

The torque converter assembly is normal.

REPAIR OR REPLACE TORQUE CONVERTER ASSEMBLY

8.	REPAIR OR REPLACE AUTOMATIC TRANSAXLE ASSEMBLY

(a) Repair or replace the automatic transaxle assembly.

Click here

PERFORM REGISTRATION

SEE MORE:

ECU Malfunction (C1611)

DESCRIPTION If the clearance warning ECU assembly detects an internal malfunction during self-diagnosis, DTC C1611 is stored. DTC No. Detection Item DTC Detection Condition Trouble Area C1611 ECU Malfunction When either of the following conditioon is met: Sub-CPU abnormal signal

Reassembly

REASSEMBLY PROCEDURE 1. INSTALL FRONT BUMPER SIDE SUPPORT LH (a) Engage the clip as shown in the illustration. Install in this Direction (b) Install the front bumper side support LH with the bolt. Torque: 5.4 N·m {55 kgf·cm, 48 in·lbf} 2. INSTALL FRONT BUMPER SIDE SUPPOR

Lexus ES: Pressure Control Solenoid "C" Actuator Stuck Off (P07957F)

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SEE MORE:

ECU Malfunction (C1611)

Reassembly

ECM selected gear	3rd
Output speed x 5th gear ratio	Less than 6500 rpm

ECM selected gear	7th
Turbine speed - output speed x 3rd gear ratio	More than 50 rpm
Output speed x 5th gear ratio	Less than 6500 rpm

ECM selected gear	6th or 7th or 8th
Output speed x 5th gear ratio	7200 rpm or more

ECM selected gear	4th or 5th
Output speed x 3rd gear ratio	7200 rpm or more

ECM selected gear	3rd
3rd gear pass detection	Not fixed after transition to latest gear

ECM selected gear	7th
7th gear pass detection	Not fixed after transition to latest gear

ECM selected gear	4th
4th gear pass detection	Not fixed after transition to latest gear

ECM selected gear	5th
5th gear pass detection	Not fixed after transition to latest gear

ECM selected gear	8th
8th gear pass detection	Not fixed after transition to latest gear